<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8" />
		<title></title>
	</head>
	
	<body>
		
	</body>
	
	<script>
		var a = 10;
		var b = "20";
		
		var f = true;

		//加号只要碰见字符串，就变成拼接
		console.log(a+b);
		
		var c = parseInt(b);
		console.log( typeof c );
		console.log( a + c );
		
		//console.log( a + parseInt(b) );
		
		console.log( a * b );
		console.log( a / b );
		console.log( a - b );
		console.log( a % b );
		
		console.log(a + f);
		
		
	</script>
	
	
</html>



